Casing for fluid-pressure apparatus



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1,655,546 A. HOLLANDE-R 5 casina ron FLUID PRESSURE APPARATUS Filed Feb.3,-1926 2 Sheets-Sheet l U E w r o Y v fnven an @fa/w eff/...ay-

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jan. 10, 1928.

A. HoLLANDr-:R

CSING FOR FLUID PRESSURE APPARATUS 2 Sheets-Sheet 2 Filed Feb; 3, 1926ald., s/w//MQ/W n jg Patented: Jan. 1o, 192s.

UNrran STATES AIJADARA HOLLANDER, OF B-ERKELEY, CALIFORNIA, ASSIGNOR TOJACKSON P'UMIE MFG. CO., A CORPORATION 0F CALIFORNIA.

CASING FOR FLUID-PRESSURE APPARATUS.

Application led February 3, 1926. Serial No.' 85,629.

My invention is particularly adapted to multi-stage centrifugal umps,although it may be used for other4 uid pressure apparatus, such as steamturbines, water wheels,

and the like, where different pressures are available and whereimpellers are employed within a casing.

One of the objects of my invention is to provide casing elements forfluid impellers and employing fluid pressure to retaln under compressionthe inner casing surrounding the impellers.

Where my invention is applied to centrifugal-pumps I employ thedischarge pres- 16 sure therefrom between the 'casings for such fluidpressure.

Another object of my invention is apparatus of the character describedwherein large'ma'chined surfacesfor large diameter 20 machine lcuts areavoided.. Y

Another object is an apparatus of the character described with theassemblageLA of several parts insuch manner as to minimize expansion andcontraction troubles devel- 26 oped from temperature differences as forexample where hot oil is the fluid employed.

Another .object is a cheaper and more efiicient construction inapparatus of the character described.

'Other objects will appear in the drawings and specifications whichfollow.

These objects I attain by mounting the runners or lmpellers upon a shaftand within an inner casing and then enclosing 'the inner casing withinand spaced from a pressure resisting outer casing and then introducingbetween the two casings a fluid pressure from the high pressure side ofthe runners or impellers and thus employing the pres- 40 sure di'erencebetween the suction side and the discharge side of the runners orimpellers as a iiuid pressure to force together the several parts of theinner casing, which is thus exposed to compression strains rather 46than bursting strains as heretofore.

By referring to the accompanying drawing, my invention will be madeclear.

' Fig. 1 is a longitudinal cross section through a multi-stagecentrifugal pump em- 50 ployi'ng my invention. j

y Fig. 2 is' similar to Fig. 1 except that the inner casing is shown inview and is shown with a longitudinal parting joint at the plane of theaxis of rotation.

Fig. 3 is a cross section of Fig. '2 on the i line IIL-III thereof.

Throughout the figures similar numerals refer to identical parts.

The numeral 1 indicates the external or outer casing adapted towithstand an internal fluid pressure in excess of the maximum dischargepressure of the pump.'

At 2 is a suction inlet and at 3 a main driving shaft which may bedriven by any conventional 'means and has mounted thereon runners orimpellers 4, 5, 6, 7,8, 9 respectively.

These impellers are assembled upon the sha-ft with keys or splines andabut against the shoulder 10 and are held in their assembled position bythe nut 11 engaging threads upon the shaft.

I prefer to make the shoulder 10 andthe nut 11 integral with `thesleeves12, 13 respectively on the shaft 3, which sleeves form a journal'surfacewithin the end bearings 14,l

15, the latter formed within the heads 16, 17

for supporting the main shaft 3.

From the several impellers there are appropriate discharge passages, asfrom the outside of the low stage impeller 4, passage 18 leads' thefluid to the suction side of the runner 5 thence discharged through thepassageway 19 to the suction side of runner 6. From runner 6, thedischarge is conveyed through the passageway 20 over and around they endof the casing and in the direction of the arrow 21 and to the inlet ofthe runner l9.

In the runner 9 the discharge passes through passage 22 thence to thesuction of runner 8 thence through passage 23, thence to the suctionside of runner 7 and is dischargedl is provided with the head 17 on one`end and the head 44 at the other end.

This inner'casing 26 is preferably made in two halves as best shown inFigs. 2 and 3 and its interior portion` is bored out to receive theseveral intermediate discs or guide'vane members between the runners.

The guide vane member between runners 4 and 5 is indicated at 28 and isprovided with a flange or tongue connection between its periphery' andthe interior of the casing 26 as shown at 29 so that when the two halvesof the casing 26 are assembled over the member 28 a groove in 26receives theA tongue 29 so that the member 28 is held in fixed relationwith respect to the runners on either side thereof.

Similar guide vane members are. shown at 30, 31, 32 and 33 between theother runners respectively andthe two halves of the inner casing 26 arepreferably bolted together on a longitudinal plane joint as shown by theholding bolts 34, 84.

The outer diameter of the casing 26 is less than the inner diameter ofthe casing 1, whereby the fluid pressure space or chamber is formed'andthis chamber is adapted to receive the discharge pressure from the innercasing at 24 which now finds its way about the entire external surfaceof the inner casing 26, and within the outer casing 1 and into the endspace 42.

This discharge pressure is in excess of any of the pressures inside ofthe inner casing 26 and consequently there will be exerted on the outersurface of the said inner casing, pressures tending to collapse ortocompress all of the said inner casin parts towards the center indicatedgeneral y by arrows 66, and from the end chamber 42` pressure will beexerted in the direction of the arrow 43 forcing the said inner casingas an assembled unit against the outer casing portion at the joint 45 ofthe main casing 1.

The bearings 14 and 15 telescope within sleeve portions of the outercasing asfshown at 50, 51 respectivelly.

Conventional pac ing means may be provided `as at 52 and plug at 54 tofacilitate the operation in assembling and adjusting the parts.

Expansion lmembers or elastic packing is shown at 60, 61 for holding theinner casing 26 normally tight against the outer casing 1 at the joint45 when no inner pressures are being developed as for assembling andtransportation.

The operation is as follows:

Assuming that hot oil is being pumped, the said oil enters thilough theconnection 2, is forced by the runners .4, 5, 6, 9, 8, 7, successivelyfrom the low pressure to the disv charge pressure at 24. This dischargepressure fills the chamber. 40 withinthe outer casing 1 and exerts acompression against the entire exposed surfaces of the inner casing 26and head 17 as indicated by the arrows 66, 66 and 43 respectively.

paratus.

oil cause a variation in the expansion and contraction ofthe innercasing with respect to the outer casing and at such times a relativemovement takes place between the parts without disturbing the assembledrelationship of the several parts or the operation of the shaft andimpeller means, the said expansion and contraction being compensated forby slight movements in the elastic packing at 60, 61. This packingperforms the function of retaining the parts in their assembled relationat such times as there is no' discharge pressure being generated by theapparatus.

It will now be seen that the 'outer casing 1, is an extremely simple oneto mold, to cast and. to machine.

All of the intricate molding and casting work is done on the innercasing portions all of which are subjected to compression strains asdistinguished from tension strains.

Smaller cross sections and hencevv a less weight of metal may thereforebe employed in these inner casing portions and relatively little machinework is necessary on them.

'Ihe alignment of the shaft with the inner casing portions is at alltimes maintained regardless of expansion or contraction, thus avoidingItemperature displacement troubles so often met with in large centrifugalap- Although as applicable to a centrifugal pump, it will T havedescribed my invention now be seen that it may be employed with equalfacility, where pressure uid is ad- -mitted at 24 and discharged at 2,as would be the case where apparatus of this generalv pe is employedtogenerate power rom fa water and in such case the higher pressure wouldalso function through the chamber or spaces 40, 40 and 43 to compressthe several arts of the inner casing and hold them ound in tight oerative relationship.

The gist of t e invention is the maintenance of apressure between anouter shell and an inner casin wherein is contained impeller means sai-pressure establishing compression exerted in the material of the innercasing.v

Particular attention is directed to the fact that the inner casing with,its impellers and enclosed parts forms a complete centrifugal pump, andis to be fully assembled before mtroductlon vinto the outer casing,"into which it is then inserted as a unit structure and the outer casingis anadditional struc y tural element having a seat for the pump toseparate the inlet and outlet pressures and w en all assembled andloperated the discharge pressure from the centrifugal pump isestablished and maintained around the inner casing and against the end'of the inner casing,l thus causing a compression stress towards thesuction end and which stress is in excess of the internal pressures ofthe pump. There are therefore no resultant stresses to cause aseparation between the different pump stages, these being held by theexcess compression against the end of the pump.

I claim:

l. In a centrifugal pump, an inner casing, an outer casinghaving an openend, a removable cover for said open end, said casings being spacedcircumferentially, a fiuid inlet to each of said casings, a dischargepassage from said inner casing communlcating with the space between saidcasings, a discharge outlet in said outer casing communieating with saidspace, impeller meanswith# in the inner casing and a shaft on which saidimpellers are mounted, a shaft bear-A ing on said inner casing and asecond shaft bearing in said outer casing' and closure means betweensaid space and said inlets comprising contacting machined surfaces onsaid casings and an elastic compression member interposed between saidcasings establishing an initial compression between said surfaces. v

2.' In hydraulic pressure appara us an outer casing and an inner casingmounted in said outer casing, said casings being spacedcircumferentially, impeller means within said inner casing, an inlet insaid outer casing, `a suction port and an outlet port in said. innercasing, said outlet. port discharging into said space whereby pumpedfluid pressure is established externally on said inner casing, adischarge port from said outer casing communicating with said space,sealing means between the casings closing said inlets from said spaceand an elastic Amember' interposed between the casings at the endopposite said sealing means. 3. In hydraulic pressure apparatus an outercasing and an inner casing mounted therein, said casings being spacedcircumferentially, a shaft and impeller means in said inner casing, saidinner casing made parting .on a plane through said shaft axis, an inletport to each of said casings and an outlet port from saidl inner casingcommunicating with said space whereby umped lfluid pressure isestablished in said) space external to said inner casing, a dischargeport for said fluid pressure from said outer casing, seal! ingmeansbetween said casings at one end closing said inlets from said space andan elastic membeiI interposed between the other end portions of saidcasings.

4. In a fluid pressure 'pump a main sha-ft, impeller means on saidshaft, a casing fenclosing said impeller means, a housing enclosing andspaced from said casing, a suction inlet to said casing adjacent one endportion of said shaft, a stuiing gland around said shaft portion, anoutlet from said casing communicating with said space and acorresponding outlet through said housing, an end bearing for the otheren d of said shaft entirely enclosed within said housing, and an endseat in said housin adjacent said inlet and against which sai casing isseated.

\ ALADAR HOLLANDER.

